A bladeless turbine design was first patented by Nikola Tesla (U.S. Pat. No. 1,061,206) in 1913 for use as a steam turbine to extract energy from a working fluid. This original patent included the grouping of a series of disks and blades with identical passage holes symmetrically grouped around the rotational axis. The working fluid was introduced at a pressure and temperature through a form of nozzle at an angle on the outer perimeter of the disks. With only the passage holes in the disks as an outlet for the working fluid, it was forced across the disks radially and angularly inward to exit through an axially located flow channel leading to an outlet at one end of the disk assembly which path resulted in reduction of pressure and temperature of the working fluid and the consequent rotation of the disk assembly. This configuration is known as a Tesla, bladeless and/or disk impeller, turbine, compressor or pump. The general concept has been widely implemented as a pump, witnessed in U.S. Pat. No. 3,644,051 (Shapiro); U.S. Pat. No. 3,668,393 (Von Rauch); and U.S. Pat. No. 4,025,225 (Durant) and as a turbine witnessed in U.S. Pat. No. 1,061,206 (Tesla); U.S. Pat. No. 2,087,834 (Brown et al.); U.S. Pat. No. 4,025,225 (Durant); U.S. Pat. No. 6,290,464 (Negulescu et al.); U.S. Pat. No. 6,692,232 (Letourneau); and U.S. Pat. No. 6,726,443 (Collins et al.). In form without brackets between the disks, the bladeless turbine is referred to as a Prandtl Layer turbine as witnessed in U.S. Pat. No. 6,174,127 (Conrad et al.); U.S. Pat. No. 6,183,641 (Conrad et al.); U.S. Pat. No. 6,238,177 (Conrad et al.); U.S. Pat. No. 6,261,052 (Conrad et al.); and U.S. Pat. No. 6,328,527 (Conrad et al).
Standard practice among individual researchers and hobbyists is to combine multiple disks each of identical outer radius and chamber size in the same turbine, compressor or pump assembly. This method is referred to as a constant-geometry disk assembly and is witnessed in U.S. Pat. No. 1,061,206 (Tesla); U.S. Pat. No. 3,644,051 (Shapiro); U.S. Pat. No. 3,668,393 (Von Rauch); U.S. Pat. No. 4,025,225 (Durant); U.S. Pat. No. 4,201,512 (Marynowski et al.); U.S. Pat. No. 6,227,795 (Schmoll, III); U.S. Pat. No. 6,726,442 (Letourneau); U.S. Pat. No. 6,726,443 (Collins et al.) and U.S. Pat. No. 6,779,964 (Dial).
It has been found by others that variations in the disk shape, referred to here as disk bending, gap differentiation, variation in outer diameters of disks within a single assembly and variation in diameter of flow chambers from one disk to the next alter performances of the disk assembly. Those are listed as follows:                1. Disk bending—U.S. Pat. No. 1,445,310 (Hall); U.S. Pat. No. 2,087,834 (Brown et al.); U.S. Pat. No. 4,036,584 (Glass); U.S. Pat. No. 4,652,207 (Brown et al.).        2. Gap differentiation—U.S. Pat. No. 2,087,834 (Brown et al.); U.S. Pat. No. 4,402,647 (Effenberger).        3. Outer diameter variation—U.S. Pat. No. 5,419,679 (Gaunt et al.); U.S. Pat. No. 6,261,052 (Conrad et al.).        4. Flow chamber diameter variation—U.S. Pat. No. 2,626,135 (Serner); U.S. Pat. No. 3,273,865 (White); U.S. Pat. No. 5,446,119 (Boivin et al.); U.S. Pat. No. 6,183,641 (Conrad et al.); U.S. Pat. No. 6,238,177 (Conrad et al.); U.S. Pat. No. 6,261,052 (Conrad et al.).        
In U.S. Pat. No. 2,626,135 (Serner); U.S. Pat. No. 4,402,647 (Effenberger); and U.S. Pat. No. 5,446,119 (Boivin et al.) the spacers, hereto referred as brackets, and gaps between the disks are approached in the disclosed disk assemblies. Serner takes the bridge of the disk and bends it to induce higher efficiency in energy translation from the fluid to the rotor or vice versa. Effenberger tapers the disks to achieve a desired effect on the gap, but shows no interest in deviating from the standard practice in bracket design or outer diameter variation. Boivin et al. include on spacer with a knife-shaped deformable portion to compensate for adjustments when combining a turbomolecular bladeless pump with a stator. These variations are not applicable to the current disclosure. U.S. Pat. No. 4,586,871 (Glass) teaches about hollow composite disks to reduce the stresses on the outer perimeter of the disks. The inventor's design of spacing the disks appears to be axially homogenous regarding thickness and geometry along the x-axis. The inventor refers to inner fences used to guide the fluid and space the disks apart, which act as spacing elements. This method of inner fences are comprised of individual curved, flat strips of material placed between the disks through welding or brazing do not constitute a single solid bracket or spacer as outlined in this disclosure. Glass' method of spacing disks through brazing or welding multiple fences between disks for guiding fluid is further disclosed in U.S. Pat. No. 4,416,582 (Glass) and U.S. Pat. No. 4,036,584 (Glass) where the disks themselves are shown to be conical or bent in design while the inner fences are shown to lie on the sloping section of the disks. U.S. Pat. No. 7,192,244 (Grande et al.) teaches of a bladeless turbine application where the disks are bent, similar to Glass above, or shaped into an axially conical fashion. Flat spacers between tie disks are placed on the sloping perimeter of the assembly and are not noted to be combined into a single bracket or spacer on a per gap basis as disclosed in the current invention. Further, no specific geometry of the spacers is noted by Grande et al. other than being apparently flat with uniform thickness according to the illustrations resembling a large washer. U.S. Pat. No. 1,139,562 (Nash) implements annular plates consisting of a plurality of vanes mounted in opposite directions so as to provide transverse openings or ports to provide two steam passages. Nash demonstrates vanes comprised of straight and flat material angled with a slope in the axial direction but remain homogeneous thickness in the axial direction. U.S. Pat. No. 1,061,142 (Tesla) discloses disks with spokes which are preferably bent. To space these disks, Tesla implements standard washers which are located at the axis of rotation or shaft but do not extend beyond the hub of a neighboring disk or into the flow channel diameter of a neighboring disk as to block the flow channel as disclosed by Tesla. Although, the bracket/spacer design disclosed here appears to be a fit for the disks in Tesla's patent, no effort is made by Tesla to include such a component. No brackets or spacers beyond a standard washer are disclosed in the drawings.
These issues have brought about the present invention.